The invention relates to a drum controller, especially for use in an air induction duct apparatus for a multiple-cylinder internal combustion engine, according to the preamble of claim 1 and the preamble of claim 5.
In an induction duct apparatus according to EP B 0 177 794, single induction ducts are combined with a combination induction duct in a single unit to which, as an additional component, an air intake manifold is flange-mounted, which is in communication on the one hand with the combination induction duct through a throttle valve and on the other hand with the single induction ducts. The second single induction ducts can be shut or opened by flap valves which are disposed on shafts which pass through the air intake manifold. This known induction duct apparatus is comparatively complicated to make and presents problems with regard to trouble-free cooperation of the flap valves mounted in the air intake manifold with the second single intake ducts disposed in a different component part.
An induction duct apparatus for a multiple cylinder internal combustion engine is disclosed in DE A 42 44 504. The intake apparatus has a tubular intake manifold from which first single intake ducts depart, which extend in an arc around the intake manifold and lead to the individual cylinders of the two rows of cylinders. Second, shorter single intake ducts likewise depart from the intake manifold and lead into the corresponding single intake ducts. The intake manifold and the first and second single intake ducts are formed by a one-piece component which has a longitudinal bore. A drum controller is inserted into the longitudinal bore and has an opening for each second single intake duct which by rotation of the drum controller can be brought into or out of alignment with the particular second single intake duct. It has been found that such a drum controller produces turbulence in the air intake. This turbulence leads in certain states of engine operation to a loss of power in the multiple-cylinder internal combustion engine. The turbulence is disadvantageous especially where the drum controller extends through all of the air intake ducts and produces a great change in the shape of the duct in the intake ducts which are not closed by the drum controller but must remain open.
The invention is therefore addressed to the problem of creating a drum controller which avoids the disadvantages described, is easy to manufacture, and has no adverse effect on the air intake.
This problem is solved, setting out from the preamble of claim 1, by the distinctive features thereof.
The advantage of the invention is that the drum controller consists of two components. It consists on the one hand of a moving control barrel, and on the other hand of a fixed core, while the opening and closing of the single intake duct is performed by the rotation of the control barrel. The fixed core has the purpose of optimizing the flow-affecting shape of the single intake duct.
According to an embodiment of the invention the fixed core is connected at least at one end to the intake manifold. A plug-in joint or a screw connection, for example, is suitable for fastening the core. In the area of the single intake ducts the fixed core is supported by appropriate bearing points or bearing areas, and indirectly by the drum controller. The drum controller, which extends over all the single intake ducts, is provided with openings in the individual ducts which must not be closed, such that both in the closed position and in the open position the shape of the flow of the open single intake duct is not impaired.
An alternative solution to the problem calls for providing the drum controller with valves, the drum controller and valve system being attached by a mounting part to the intake manifold. This design is especially simple and is characterized in that here too the drum controller has but a slight effect on the air flow in the single ducts that are not to be closed.
The mounting part can, according to an advantageous embodiment of the invention, be joined to an intermediate intake duct flange. Both the fastener and the drum controller valve combination can be pre-mounted and thus can be built economically into the intake manifold.
These and additional features of preferred embodiments of the invention will be found not only in the claims but also in the description and the drawings, the individual features being applicable individually or severally in the form of subcombinations in the embodiment of the invention and in other fields and may represent advantageous as well as independently patentable embodiments, for which protection is hereby claimed.